The correct answer would be A "<span>A light-year is the distance light travels in a year.
This is considered a unit of distance connected to the distance that light can travel in one year. It is proved that light travels at 300,000 km per second so, in 1 year, it might travel 10 trillion km.
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Answer:
D
Explanation:
Trees are obviously effected from deforestation.
Pollution effects the things trees need to grow (water, air).
Reduction removes parts of the tree, some parts being needed.
Answer:
Question 1: D
Question 2:D
Explanation:
Question 1: D
Question 2
mass=m=65kg
Acceleration due to gravity=g=9.8m/s^2
Height=h=7 meters
Potential energy=m x g x h
Potential energy=65 x 9.8 x 7
Potential energy=4459 joules
Answer:
t_total = 6.99 s
Explanation:
It asks us how long it takes to hear the sound, for this we must look for the time (t₁) it takes for the sound to reach the microphone, the time it takes for the video signal (t₂) to reach the television and the time (₃) it takes for the TV sound to reach us, so the total delay time is
t_total = t₁ + t₂ + t₂
we look for t1, it indicates that the distance x = 22m
v = x / t
t = x / v
t₁ = 22/343
t₁ = 6.41 10-2 s
time t₂
t₂ = 4500 103/3 108
t₂ = 1.5 10-5 s
time t₃
t₃ = 2/343
t₃ = 5.83 10⁻³
Total time is
t_total = t₁ + t₂ + t₃
t_total = 6.41 10⁻² + 1.5 10⁻⁵ + 0.583 10⁻²
t_total = 6.99 s